Revert of Tidy up SkNx_neon. (patchset #3 id:40001 of https://codereview.chromium.org/2196773002/ )
Revert of Tidy up SkNx_neon. (patchset #3 id:40001 of https://codereview.chromium.org/2196773002/ )

Reason for revert:
https://luci-milo.appspot.com/swarming/task/3055149a25621b10

Not Nexus 5 specific.   Reproduces on Pixel C with --gcc -t Debug -d arm_v7_neon.  Not sure about other configs yet.

Original issue's description:
> Tidy up SkNx_neon.
>
> This takes advantage of the fact that all the compilers we use that
> support NEON implement it with their own vector extensions.  This means
> normal things like c = a + b work on the underlying vector types already.
> Odd instructions like min or saturated add need to stay intrinsics.
>
> Also, rearrange functions to a more consistent order.
>
> BUG=skia:
> GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2196773002
> CQ_INCLUDE_TRYBOTS=master.client.skia:Test-Ubuntu-GCC-GCE-CPU-AVX2-x86_64-Release-SKNX_NO_SIMD-Trybot
>
> Committed: https://skia.googlesource.com/skia/+/6ad22315eb6eacfcd35497cd118440a619d05b18

TBR=msarett@google.com,mtklein@chromium.org
# Not skipping CQ checks because original CL landed more than 1 days ago.
BUG=skia:

Review-Url: https://codereview.chromium.org/2196953002

aosp-mirror/platform_external_skia,google/skia,rubenvb/skia,Hikari-no-Tenshi/android_external_skia,Hikari-no-Tenshi/android_external_skia,rubenvb/skia,aosp-mirror/platform_external_skia,google/skia,HalCanary/skia-hc,google/skia,rubenvb/skia,Hikari-no-Tenshi/android_external_skia,aosp-mirror/platform_external_skia,rubenvb/skia,HalCanary/skia-hc,rubenvb/skia,HalCanary/skia-hc,Hikari-no-Tenshi/android_external_skia,rubenvb/skia,aosp-mirror/platform_external_skia,HalCanary/skia-hc,aosp-mirror/platform_external_skia,HalCanary/skia-hc,rubenvb/skia,HalCanary/skia-hc,HalCanary/skia-hc,Hikari-no-Tenshi/android_external_skia,HalCanary/skia-hc,HalCanary/skia-hc,aosp-mirror/platform_external_skia,google/skia,google/skia,Hikari-no-Tenshi/android_external_skia,rubenvb/skia,google/skia,rubenvb/skia,aosp-mirror/platform_external_skia,Hikari-no-Tenshi/android_external_skia,aosp-mirror/platform_external_skia,aosp-mirror/platform_external_skia,aosp-mirror/platform_external_skia,google/skia,google/skia,rubenvb/skia,google/skia,HalCanary/skia-hc,Hikari-no-Tenshi/android_external_skia,google/skia